Conveying continuous web having cross-direction tension

ABSTRACT

An apparatus for handling a continuous web in a continuous processing operation wherein the web incorporates therein one or more stretched elastic-type elements having retractive forces active in the cross-machine direction, and limiting shrinkage of the web in the cross-machine direction to no more than about 5%. Shrinkage in the width dimension is controlled using methods including transporting the web on a sequence of rolls having on their outer working surfaces protuberances which interact with edges of openings in the web, inhibiting lateral movement of elements defining the edges of the openings, and thereby stabilizing the web in the width dimension.

This is a divisional application of copending application Ser. No.08/382,109, filed on Jan. 31, 1995 U.S. Pat. No. 5,552,007.

FIELD OF THE INVENTION

This invention relates to handling a continuous web in a continuousprocessing operation wherein the web incorporates therein one or moreelastic-type elements having retractive forces active in thecross-machine direction, while avoiding reduction of the width of theweb due to such retractive forces.

BACKGROUND OF THE INVENTION

It is known to incorporate elastic-type elements into a continuous webin a continuous processing operation wherein the elastic elements extendin the longitudinal, or machine, direction in the web. Such elasticelements may be incorporated in such manner that the elements are in astretched state, having retractive forces active in the longitudinal, ormachine, direction, during the continuous processing of the web. So longas such retractive forces are confined to the machine direction, theeffect of the retractive forces on the registration of the web can becontrolled by controlling the tension on the web.

In continuous processing of a substantially endless web, as in theinstant invention, it is known to perform a plurality of processingsteps on the web in sequence. Typically, it is desired to perform one ormore of the processing steps at specific locations in the web, wherein asecond step is performed at a particular locus with respect to a first,or previous, step, whereby it is critical to be able to locate, at thework station for performing the second step, the location at the whichthe previous step was performed. In the art, this is known as being ableto "register" the second step with respect to the first step.

A first factor in being able to register a second processing step withrespect to a first processing step, is being able to determine thedistance, and the direction, that the work locus on the web where thefirst step was performed, has travelled from the location in theprocessing apparatus where the first step was performed. Suchdetermination can be divided into four assessment steps.

First, one determines the longitudinal distance, in the machinedirection, travelled by the work locus in the web.

Second one determines the width distance, in the cross-machinedirection, travelled by the work locus.

Third, one determines shrinkage in the machine direction.

Fourth, one determines shrinkage in the cross-machine direction.

The first and third factors can be measured and controlled usingconventional control apparatus and methods to control drive speed andtension in the web. The second factor can be controlled usingconventional lateral guide apparatus and methods.

The fourth factor is normally accommodated as a dependent dimensioncontrolled by the amount of tension/tensile stress imparted to the webin the machine direction. Namely, as tensile stress is applied to theweb in the machine direction, the amount of strain/stretch in themachine direction produces a dependent amount of shrinkage in the web inthe cross-machine direction.

Such accommodation, however, assumes that no retractive-type forces areactive in the web in the cross-machine direction. To the extentretractive-type forces are active in the web in the cross-machinedirection, absent other controls, the web shrinks in the width(cross-machine) direction in response to such active retractive-typeforces, thereby changing the width of the web in the cross-machinedirection. In processing operations where it is important to maintain aconstant, or nearly constant width in the web, other means are needed tomaintain constant the width of the web.

It is known to maintain the width of the web using a tenter frame,wherein an assemblage of gripping devices grips the opposing edges ofthe web at closely spaced locations, and travels with the web, thusphysically restraining the web against reduction in the width dimensionso long as the gripping devices have hold of the edges of the web.

Use of tenter frames have four severe limitations. First, they occupyprecious working space adjacent the web being processed such that theymay interfere with set-up and/or operation of the processing steps whereby the web is otherwise modified.

Second, tenter frames are relatively complex, expensive mechanicaldevices.

Third, use of tenter frames is generally limited to straight stretchesof the processing line. Namely, tenter frames generally are not used tomaintain the width of the web as the web traverses about thecircumference of a turning roll or a processing roll in the sequence ofsteps in the processing line. Yet turning rolls and processing rolls arecommonly preferred as efficient rotary devices for performing routinesteps on webs being processed.

Fourth, the edges of the web gripped by the tenter frame grippers aregenerally not subsequently used as part of the finished product, wherebythe grippers may make a positive contribution to the amount of wasteassociated with the manufacturing operation.

Another known method for urging width-dimensional stability on a webunder cross-machine direction tension is to process the web on a rollcoated with silicone rubber, as taught in, for example U.S. Pat. No.4,925,520 Beaudoin et al. However, a silicone rubber coating presents anumber of limitations related to the characteristics of silicone rubber.For example, silicone rubber on a roll carrying the web cannot providesufficiently rigid surface against which to perform slitting and likecutting operations.

Thus, it would be desirable to provide additional methods and apparatusfor controlling the dimensional stability of a web in the cross-machinedirection wherein the web incorporates therein retractive-type forcesactive in the cross-machine direction.

It is an object of this invention to provide apparatus and methods forproviding cross-machine dimensional stability in a continuous web beingprocessed in a continuous process, the web having stretched elastic-typeelements which exhibit retractive-type forces active in thecross-machine direction.

It is a further object to provide such apparatus and methods, includinga first rotary transport device, transporting the web, including a firstset of protuberances thereon for engaging and holding the web, andtransferring the web to a second rotary transport device including asecond set of protuberances thereon for engaging and holding the web.

It is a further object to provide such apparatus and methods wherein thefirst and second rotary transport devices have outer working surfaces,carrying the web, which outer working surfaces are aligned with eachother across the entire width of the web.

It is yet another object to provide such apparatus and methods whereinthe composition of one or more of the outer working surfaces comprisesan outer coating incorporating a release agent such aspolytetrafluoroethylene.

It is still another object to provide apparatus and methods includingsuction into one or both of the rotary transport devices.

Yet another object is to provide apparatus and methods wherein the widthdirection shrinkage of the web is limited to no more than about 5%,preferably no more than about 1%, most preferably no more than about0.5%.

SUMMARY OF THE INVENTION

This invention describes methods and apparatus for handling, conveying,transferring, transporting, and the like, a continuous web incorporatingstretched elastic-type elements having a retracting force active in thecross-machine direction while maintaining the overall width of the web,thus minimizing shrinkage of the web in the width dimension.

A first family of embodiments of the invention comprises a method ofhandling a continuous web in a process wherein the web advances in themachine direction, the web having a length defined in the machinedirection and a width defined in the cross-machine direction betweenfirst and second edges of the web, wherein substrate elements of the webdefine openings therebetween into the web, and edges of the openings.The method comprises the steps of incorporating into the web stretchedelastic-type elements having a retracting force active in thecross-machine direction and urging effective reduction in the width ofthe web; transporting the web on a first outer working surface of afirst rotary transport device, the first outer working surface includinga first set of protuberances thereon, the first set of protuberancesinteracting with the substrate elements defining the edges of a firstset of the openings into the web and thereby inhibiting lateral movementof the respective substrate elements defining the edges of the first setof openings, and stabilizing the width of the web in the cross-machinedirection between the first and second edges of the web on the firstrotary transport device; and transferring the web from the first rotarytransport device to a second outer working surface of a second rotarytransport device, the second outer working surface including a secondset of protuberances thereon, the second set of protuberancesinteracting with the substrate elements of a second set of the openingsinto the web and thereby inhibiting lateral movement of the respectiveedges of the second set of openings, and stabilizing the width of theweb in the cross-machine direction between the first and second edges ofthe web, during the transferring step.

In preferred embodiments, the method includes aligning the first andsecond outer working surfaces at the locus of closest approach of thefirst and second outer working surfaces, preferably across the entirewidth of the web, while transferring the web from the first rotarytransport device to the second rotary transport device.

It is also preferred that the first and second rotary transport devicescomprise respective first and second substrates, with the substratescomprising respective first and second supports for the respective firstand second outer working surfaces, and first and second coatings on therespective first and second substrates, the first and second coatingsincorporating the protuberances, and including first and second releaseagents, preferably comprising polytetrafluoroethylene, in the respectivecompositions of the first and second coatings.

Preferred methods include drawing suction into one, preferably both, ofthe first and second rotary transport devices, and thereby assisting instabilizing the web on the respective rotary transport devices.

The methods of the invention are typically effective to retain the widthof the web such that shrinkage in the cross-machine direction, betweenthe first and second edges of the web, during processing of the web onthe first and second rotary transport devices, is no more than about 5%,preferably no more than about 1%, most preferably no more than about0.5%.

In some embodiments, the method includes maintaining a gap between thefirst and second rotary transport devices at the locus of transferringthe web from the first rotary transport device to the second rotarytransport device. In other embodiments, the method includes maintaininga nip at the locus of transferring the web from the first rotarytransport device to the second rotary transport device, and applyingpressure on the nip while transferring the web from the first rotarytransport device to the second rotary transport device.

In preferred embodiments, the first and second rotary transport deviceshave corresponding first and second circumferences, and the first andsecond sets of protuberances circumscribe the respective circumferencesof the first and second rotary transport devices.

In highly preferred embodiments, the second set of protuberancesinteracts with the substrate elements defining the edges of the secondset of openings into the web adjacent the first and second edges of theweb, and thereby inhibits lateral movement of the first and second edgesof the web during the transferring step, such that the overall effect ofthe method is to retain the width of the web such that shrinkage in thecross-machine direction during the transferring step is no more thanabout 5%.

In typical operation, the sizes of the openings into the web are trivialcompared to the width of the web, such that the web comprises agenerally uniform structure, and may comprise a porous structure.

In a second family of embodiments, the invention comprehends apparatusfor transporting a continuous web in a process wherein the web advancesin a machine direction, the web having a length defined in the machinedirection and a width defined in the cross-machine direction betweenfirst and second edges of the web, wherein substrate elements of the webdefine openings therebetween into the web, and edges of the openings,the web including therein stretched elastic-type elements having aretracting force active in the cross-machine direction and urgingeffective reduction in the width of the web, the apparatus comprising afirst rotary transport device having a first outer working surface, thefirst outer working surface including a first set of protuberancesthereon, the first set of protuberances being adapted to interact withthe substrate elements defining the edges of a first set of the openingsinto the web and thereby to inhibit lateral movement of the respectiveedges of the first set of openings, and stabilize the width of the webin the cross-machine direction between the first and second edges of theweb on the first rotary transport device; and a second rotary transportdevice disposed in working relationship with the first rotary transportdevice to receive a web transferred from the first rotary transportdevice, and having a second outer working surface, the first and secondouter working surfaces being aligned with each other at the locus ofclosest approach of the first and second outer working surfaces, thesecond outer working surface including a second set of protuberancesthereon, the second set of protuberances being aligned with the firstset of protuberances along the direction of advance of the web, andbeing adapted to interact with the substrate elements defining the edgesof a second set of the openings into the web, and thereby to inhibitlateral movement of the respective edges of the second set of openings,and stabilize the width of the web in the cross-machine directionbetween the first and second edges of the web, during transfer of theweb from the first rotary transport device to the second rotarytransport device.

Preferably, the first and second outer working surfaces are aligned witheach other at the locus of closest approach of the first and secondouter working surfaces, across the entire width of the web, fortransferring the web from the first rotary transport device to thesecond rotary transport device.

Also preferably, the first and second rotary transport devices compriserespective first and second substrates comprising respective first andsecond supports for the respective first and second outer workingsurfaces, and first and second coatings on the respective first andsecond substrates, the first and second coatings incorporating theprotuberances, and including first and second release agents, preferablyincluding polytetrafluoroethylene, in the respective compositions of thefirst and second coatings.

One, and preferably both, of the first and second rotary transportdevices incorporates suction apparatus therein, thereby to assist instabilizing the web on the respective rotary transport devices, theoverall effect of the apparatus being to retain the width of the websuch that in the cross-machine direction, between the first and secondedges of the web, is no more than about 5%, preferably no more thanabout 1%, most preferably no more than about 0.5%.

The apparatus, as set up, preferably includes a gap between the firstand second rotary transport devices at the locus of transferring the webfrom the first rotary transport device to the second rotary transportdevice. However, the invention does comprehend some embodiments whereinthe apparatus incorporates a nip at the locus of transferring the webfrom the first rotary transport device to the second rotary transportdevice, and means for applying pressure on the nip while transferringthe web from the first rotary transport device to the second rotarytransport device.

In some embodiments, the first and second rotary transport devices havecorresponding first and second circumferences, and the first and secondsets of protuberances circumscribe those respective circumferences.

In typical operating arrangements of the apparatus, the second set ofprotuberances is adapted to interact with the substrate elementsdefining the edges of the second set of openings into the web adjacentthe first and second edges of the web, thereby to inhibit lateralmovement of the first and second edges of the web during transfer of theweb from the first rotary transport device to the second rotarytransport device, the apparatus being effective to retain the width ofthe web such that shrinkage of the web in the cross-machine direction,during such transfer is no more than about 5%, preferably no more thanabout 1%, most preferably no more than about 0.5%.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be more fully understood and furtheradvantages will become apparent when reference is made to the followingdetailed description of the invention and the drawings, in which:

FIG. 1 is a top view of a finished garment which may be made usingmethods and apparatus of this invention.

FIG. 2 is a top view of a finished garment blank, as a workpiece in acontinuous web, from which the garment of FIG. 1 can be made.

FIG. 3 is a schematic representation of a side elevation view of aportion of a processing line incorporating processing rolls usingapparatus and method of the invention.

FIG. 4 is a top view of a fragment of one of the processing rolls, takenat 4--4 of FIG. 3.

FIG. 5 is a fragmentary cross-section of a process roll, showing arepresentative coating applied to rolls of the invention, andincorporating protuberances therein, taken at 5--5 of FIG. 4.

FIG. 6 is an enlarged cross-section of a portion of the roll of FIG. 5,taken at the broken circle 6 in FIG. 5.

FIG. 7 is a graphical representation of the effective downward force onthe web across the width of the web.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT

The following detailed description of the illustrated embodiments ismade in the context of making panty-type undergarments, and includesapparatus and methods related to processing a web corresponding to onelayer of material such as nonwovens and films, preferably two superposedlayers of spunbonded polypropylene material, e.g. 0.7 ounce per squareyard (osy) each, including performing a plurality of process steps ateach of a plurality of registered locations on the web.

The specific context is the production of disposable garments in acontinuous combined web containing one or more such layers of material.The garment preforms in the web extend transversely across the width ofthe web, with the waist portions of the garments extending in themachine direction of the web along or adjacent corresponding opposingside edges of the web. The front and back portions of the garments areon opposing sides of the web. In the embodiments illustrated, theapparatus and methods are concerned with maintaining constant thecross-machine width dimension of the web while the web is beingprocessed through the several processing steps.

It is generally known to make a garment 10 of the type shown in FIG. 1.Such garments typically comprise an assemblage of two or more layers orpartial layers of woven or non-woven fabric or films, along with otherelements. Elastic may be used at the waist 12, in the body portion 14,and around the leg openings 16.

In this context, as in most such processes for fabricating the garmentas at 10, a blank 18 such as that shown in FIG. 2 is first made as partof a continuously processed web of material. After the blank is fullyfabricated, the sideseams 20 are formed and the garment is severed fromthe web either as a blank, fully finished or partially finished, or as afully formed garment article.

The process contemplated by the invention includes forming adjacentleading and trailing blanks 18A and 18B in the web as illustrated inFIG. 2. In the blanks shown, front elastic elements 22, crotch elasticelements 24, and back elastic elements 26 are disposed, in a stretchedcondition in the web, adjacent the edges of the respective leg openings16, with the respective stretched elastic elements oriented indirections generally following the contours of the edges of the legopenings 16. Each of such elastic elements 22, 24 and 26 includes one ormore segments which extends in a direction transversely across the widthdimension "W" of the web (cross-machine direction, or CMD). Suchstretched elements, by nature, exert retracting forces active in thecross-machine direction and urge effective reduction in the width "W" ofthe web.

FIGS. 3-6 illustrate one embodiment of the apparatus and methods of theinvention. Referring now to FIG. 3, a continuous web 28 enters theportion 29 of the processing line shown at a first turning roll 30,passing under the turning roll 30 and into a nip 68 between the turningroll 30 and elastic incorporation roll 32. At one or more work stations,not shown, on elastic incorporation roll 32, elastic elements 22, 24 and26 are incorporated into the web 28 in stretched condition, in thepositions they ultimately occupy in blank 18 and garment 10. Typically,the elastic elements are stretched about 100% to about 300% at the timethey are incorporated into the web 28.

From the elastic incorporating roll 32, the web 28 passes under a secondturning roll 34 and onto the surface of construction roll 36. At one ormore work stations 37 generally represented as rolls on constructionroll 36, additional work is done on web 28 in fabricating blanks, inserial fashion along the generally endless length of web 28, such that aseries of blanks 18, or blank pre-forms, are fabricated in the web 28,one following the other, generally as shown at 18A and 18B in FIG. 2.

From construction roll 36, the web 28 passes under anvil roll 38, andbetween anvil roll 38 and cutter roll 40. From anvil roll 38, web 28passes over third turning roll 42 and on to further processing beyondthe scope of this invention.

Still referring to FIG. 3, the elastic elements 22, 24, and 26 exertretractive forces in the web 28, in the cross-machine direction,beginning at the elastic incorporation roll 32, and all along the webfor the remainder of the length of the portion of the processing systemillustrated in FIG. 3, including through the work stations 37. Workperformed at work stations 37, and at anvil roll 38, requiresregistration of each blank pre-form with the working elements at therespective work station. Accordingly, the web dimensions should bestable, both the length dimension of the web and the width dimension ofthe web, through the processing operation represented by the portion 29of the processing line.

Referring to FIGS. 4-6, the outer circumference of the construction roll36 generally includes a substrate 44 which extends entirely about thecircumference of the construction roll, and along the entire length "L"of the roll, which corresponds generally with the width "W" of the web28.

A first coating 46 comprising rubber or like resilient material extendsentirely about the circumference of the construction roll 36 and alongonly a central portion "LC" of the length of the roll.

A second coating 48 has a composition incorporating primarily metallicelements. Coating 48 extends entirely about the circumference of theconstruction roll, and along first and second portions "LE1" and "LE2"of the length "L" of the construction roll, adjacent the first andsecond ends 50 and 52 of the roll.

Referring to FIGS. 4 and 5, a series of suction ports 54 communicatesuction from inside the construction roll 36, urging the web 28 firmlyagainst the composite of the outer working surface 56 of the roll 36,the composite of the outer working surface including the coatings 46 and48, as well as uncoated portions 49 of the outer surface of thesubstrate 44.

Referring to FIG. 6, the second coating 48 is preferably applied as agenerally metallic composition, by plasma or other high temperatureapplication process. For example, coating 48 may be applied as a plasmaspray, or using an electric arc medium. Such coatings are available fromPlasma Coatings Inc., Waterbury, Conn. A preferred such coating isavailable from Plasma Coatings Inc. under the designation of productnumber 936.

Using the application processes above mentioned, the resulting coating48 is characterized by an irregular surface texture, includingprotuberances 58 spaced about the coating surface at random, thoughclosely spaced, locations. Depending on the method of application used,and the exact composition used, the surface of coating 48 may resemblethe working surface of conventional sandpaper. The roughened surfacecomprising an array of protrusions extending outwardly at least about0.006 mm preferably up to about 3 mm, more preferably between about 0.01mm and about 0.03 mm. In some applications, as in the instantapplication to holding a continuous web dimensionally stable duringtransfer from one roll to another, the surface of the coating 48 neednot be so aggressive, and so appears more like the working surface ofdull, or used, sandpaper.

In combination with the protuberances 58, the surface of coating 48correspondingly includes valleys 60 about the respective protuberances.

The exact nature of any particular metal-based coating 48 dependssomewhat on the composition used, and the method of applying it.Accordingly, the protuberances of the applied coating may becharacterized as quite aggressive, like fresh sandpaper, or may be moremuted, like used sandpaper. The coating 48 may incorporate therein oneor more agents to assist the release of the web from the workingsurface, such as polytetrafluoroethylene, commonly sold under the tradename Teflon® by the DuPont de Nemours Corporation, Wilmington, Del.

In the application at hand, the web 28, as it enters the processdepicted at turning roll 30, can be generally represented as aconventional porous spunbonded polypropylene nonwoven, 0.7 ounces persquare yard, having a generally entangled mat of polypropylene fibers.Additional layers of like material may be added to the web 28 as itprogresses through the several processing steps.

FIG. 6 illustrates that, as the web 28 is urged against coating 48, e.g.by normal tension in the web or by suction drawn by the respective rolls32, 34, 36, or 38, the protuberances 58 project into the web at existingopenings in the spunbonded web between the fibers. As the protuberancesenter the web under the urging of suction or the longitudinal tension inthe web, they expand existing spaces between the fibers, to create afirst set of expanded openings 62 having edges, with fiber elements ofthe web being disposed at those edges, in engagement with theprotuberances.

While protuberances 58 may extend entirely through the web, such isgenerally not the case and is not necessary. By extending substantiallyinto the thickness "T" of the web as shown in FIG. 6, the protuberancesengage the fibers of the web about generally the entire area of the weboverlying the area coated with coating 48, with sufficient engagementthat the web is held dimensionally stable, against especially theretractive forces of the elastic as applied in the cross-machinedirection. As seen in FIG. 4, the coating 48 extends to the ends 50 and52 of the construction roll 36, such that the edges 64 of the web 28 areunderlain with coating 48. Correspondingly, the respective protuberances58 underlying the web at edges 64 engage the web at even the outerextremities of edges 64, thereby to hold the web dimensionally stableagainst the width dimension retractive forces being exerted by theelastic elements 22, 24, and 26, even at edges 64.

FIG. 7 represents the effective downward pressure on a web across itswidth "W," and therefore the effective ability of that downward pressureto hold the web dimensionally stable against lateral forces in the webtending to destabilize the web in the width dimension.

At each edge 64 of the web, the net downward pressure on the web goesfrom a general maximum pressure, represented by the flat portion of thecurve across the middle of the width "W," to zero at the outerextremities of the web. The transition from the general maximum pressureto zero pressure is represented as the transition zone labelled "E."

The width of the transition zone "E" depends on the ability of thecoating 48, in combination with the suction if any, to immobilize theedges 64 of the web in the width, or CMD, dimension of the web. Usingthe specific coating 48 described above, with the web described above,in combination with suction of about 0 to about 80 inches of water,preferably about 5 to about 15 inches, more preferably about 10 inchesof water, the reduction in width associated with the transition zone islimited to less than about 5%. If a less aggressive coating 48 is used,or if the suction is reduced, the reduction in width associated with thetransition zones increases, to the point where, without use of thecoating 48, the reduction in width may be substantially greater thanabout 5%.

In the portion 29 of the processing line shown, all rolls whichtransport the web after the elastics 22, 24, and 26 have beenincorporated in the web have a coating 48 effective to maintain the CMDdimensional stability in the web while the web is being transported onthe respective roll. All rolls also preferably include suction to assistthe coating 48 in holding the web. Thus at least rolls 32, 34, 36, 38,and 42 have a coating 48.

The web can be effectively held without any use of suction. However, useof suction minimizes the shrinkage in width, thus use of suction on eachof the rolls is preferred.

In addition, the inventors have found that the web can traverse a gap 66as shown in FIG. 3 between rolls while still maintaining the dimensionalstability of the web, so long as both rolls incorporate a coating 48suitable to engage especially the edges 64 of the web. By contrast, therolls can be satisfactorily engaged at a conventional nip, withcorresponding conventional amounts of pressure for e.g. transferring theweb 28 from one roll to another.

Since the protuberances 58 are randomly spaced in the coating 48, thecoating on each roll engages its own unique set of existing openings inthe web to thereby create its own set of expanded openings 62 whileengaged with the fibers of the web.

While not absolutely necessary, the effectiveness of maintainingdimensional stability in the web is somewhat enhanced where the outerworking surfaces 56 of respective rolls transferring and receiving theweb are aligned with each other across the entire width of the web.

The inventors have found that by using a coating 48 including thepolytetrafluoroethylene in its composition, adhesive and the likenormally aggressively adhering materials can be easily cleaned from thesurface of coating 48 without sacrificing the ability of the coating 48to hold the web 28 and thereby to maintain the dimensional stability ofthe web.

It is contemplated that the operation and functions of the inventionhave become fully apparent from the foregoing description of elements,but for completeness of disclosure, the usage of the invention will bebriefly described.

A web 28 enters the processing operation illustrated in FIG. 3 atturning roll 30, and is pressed against the elastic incorporating roll32 at nip 68. As the web is transported on roll 32, threads of elastic(not shown) are incorporated into the web at locations properlypositioned to provide the elastic properties desired in the finishedproduct, namely the garment article 10.

Once the elastics have been incorporated in the web on roll 32, the webincludes elements having retracting forces active in the cross-machinedirection and urging effective reduction in the width of the web.

From the elastic incorporating roll 32, the web 28 is transferred toturning roll 34, and from turning roll 34 to construction roll 36. Onconstruction roll 36, further work is done on the web at the workstations represented schematically as 37. From construction roll 36, theweb is transferred to anvil roll 38. Leg openings 16 are cut by cutterroll 40, against anvil roll 38. The web then passes over turning 42, andpasses out of the portion 29 of the processing line of interest in thisinvention.

Having thus described the invention in full detail, it will be readilyapparent that various changes and modifications may be made withoutdeparting from the spirit of the invention. All such changes andmodifications are contemplated as being within the scope of the presentinvention, as defined by the following claims.

What is claimed is:
 1. Apparatus for transporting a continuous fibrousweb in a process wherein the web advances in a machine direction, theweb having a length defined in the machine direction and a width definedin the cross-machine direction between first and second edges of theweb, the web including therein stretched elements exerting retractingforce active in the cross-machine direction and thereby urging effectivereduction in width of the web, said apparatus comprising:(a) a firstrotary transport device, including a first outer coating secured in saidfirst rotary transport device, said first outer coating comprising afirst outer working surface having a first set of protuberances thereon,said first set of protuberances interacting with the web to form a firstset of expanded openings in the web and subsequently interacting withthe first set of expanded openings thereby to stabilize the width of theweb on said first rotary transport device; and (b) a second rotarytransport device disposed in working relationship with said first rotarytransport device to receive the web from said first rotary transportdevice, a second outer coating being secured in said second rotarytransport device, said second outer coating comprising a second outerworking surface having a second set of protuberances thereon, said firstand second outer working surfaces being aligned with each other acrossthe width of the web, said second set of protuberances being alignedwith said first set of protuberances along a direction of advance of theweb, said second set of protuberances interacting with the web to form asecond set of expanded openings in the web and subsequently interactingwith the second set of expanded openings thereby to stabilize the widthof the web during transfer of the web from said first rotary transportdevice to said second rotary transport device.
 2. Apparatus as in claim1, said first set of protuberances comprising polyfluoroethylene. 3.Apparatus as in claim 2, said first set of protuberances comprisingpolytetrafluoroethylene.
 4. Apparatus as in claim 1, said first rotarytransport device including a suction port extending through said firstouter working surface whereby suction can be applied to the web toassist in stabilizing the width of the web on said first rotarytransport device.
 5. Apparatus as in claim 4, said apparatus beingeffective to retain the width of the web dimensionally stable such thatshrinkage in the cross-machine direction, between the first and secondedges of the web, is no more than about 1%.
 6. Apparatus as in claim 4,said apparatus being effective to retain the width of the webdimensionally stable such that shrinkage in the cross-machine direction,between the first and second edges of the web, is no more than about0.5%.
 7. Apparatus as in claim 4, said apparatus being effective toretain the width of the web dimensionally stable such that shrinkage inthe cross-machine direction, between the first and second edges of theweb, is no more than about 5%.
 8. Apparatus as in claim 1, and includinga gap between said first and second rotary transport devices at a locusof transferring the web from said first rotary transport device to saidsecond rotary transport device.
 9. Apparatus as in claim 1, said secondset of protuberances including a second release agent.
 10. Apparatus asin claim 9, said second release agent comprisingpolytetrafluoroethylene.
 11. Apparatus as in claim 1, said second rotarytransport device including a suction port extending through said secondouter working surface whereby suction can be applied to the web toassist in stabilizing the width of the web on said second rotarytransport device.
 12. Apparatus as in claim 1, said first and secondcoatings comprising primarily metallic compositions applied to saidfirst and second rotary transport devices using a high temperatureapplication process.